This invention relates to a hard surface-treating agent, stain-proofing agent and a surface-treating method using these agents, more particularly to a hard surface-treating agent for keeping the coated surfaces of vehicles such as cars and aircrafts, office furniture, buildings, etc. in a clean state for a long period of time, a stain-proofing agent for preventing the coated surfaces from being stained, and a surface-treating method using these agents.
It is already known that titanium oxide of an anatase form coated on the surfaces of tiles and glass articles renders these surfaces hydrophilic, stain-proof or antibacterial, which are caused by light-excitation of titanium oxide through its absorption of a light having a specific wavelength. It is nowadays used in various surface-treating agents.
However, normally, conventional surface-treating agents containing titanium oxide employ an acrylic silicone, etc. as a binder for keeping the titanium oxide on the surfaces. Therefore, the conventional surface-treating agents require a coating process step similar to that required for coating paints. Therefore, general users can hardly handle these conventional agents.
Car waxes are well known as a surface-treating agent for affording the surface-protecting or stain-proofing property to the coated surface of car bodies. The car waxes vary depending upon the objective performance or manufacturers"" know-how, but in general they contain a wax component and silicone oil component for protecting the car bodies, and an organic solvent or water as a dispersing medium, to which are added a surface active agent, abrasive, etc.
Since the conventional car waxes contain silicones as a main component, they cannot secure the stain-proofing performance on coated surfaces of cars, and stains adhered to the waxed coated surfaces cannot easily be washed out with water. Furthermore, the conventional car waxes cannot exhibit a xe2x80x9cself-cleaning effectxe2x80x9d that stains adhered to the surface of body can be removed by the ability of the surface itself decomposing the stains.
Still further, since conventional car waxes contain a silicone as a main component, the waxed coated surface shall have water repellency, which forms droplets of rainwater on the coated surface, which have spots of rain formed thereon when dried. Similarly, tap water used in car washing forms droplets on the coated surface, which then form spots when dried. Thus, with the conventional waxes, there is such a problem that these spots, which are generically called xe2x80x9cwater spotsxe2x80x9d, are formed on the coated surfaces.
Stains can be removed by washing with water, but the spots can hardly be removed by washing with water, or even by washing with an abrasive. The reason for this is believed that the water droplets on the coated surfaces form lenses, which cause the coating to change in its nature. Since the coated surface itself changes, the water spots can hardly be removed by a mere wiping process.
Surface-treating agents for making coated surfaces hydrophilic. or stain-proofing agents are known and commercially available. General users can hardly handle these agents, and must ask a specialist to coat these agents. Thus, the general users cannot use these agents with ease.
The object of this invention is to solve the above-mentioned problem, which the conventional surface-treating agents have. That is, the object of this invention is to provide a surface-treating agent for use in coating vehicles such as cars and aircrafts, office furniture, buildings, etc., which can keep the stain-proofing performance based on the self-cleaning effect for a long period of time, and further afford a good workability in coating of this agent. The further object of this invention is to provide a surface-treating agent for use in coating vehicles such as cars and aircrafts, office furniture, buildings, etc., which can prevent the formation of water spots, keep the water spot formation-preventing effect for a long period of time, and further afford a good workability in coating of this agent.
As a result of the inventors"" intensive studies, it has been found that the above-mentioned objects of this invention can be achieved by using the specific kind of titanium oxide fixed with a thermoplastic resin as binder.
In order to achieve the above-mentioned objects, this invention is a hard surface-treating agent characterized by comprising a dispersion of an anatase-form titanium oxide and a thermoplastic resin in an organic medium, in which the content of the anatase-form titanium oxide is within the range of 0.05 to 20 wt %, and the content of the thermoplastic resin within the range of 0.05 to 20 wt %, and a stain-proofing agent characterized by comprising a dispersion of the anatase-form titanium oxide and a thermoplastic resin in an organic medium, in which the content of the anatase-form titanium oxide is within the range of 0.05 to 20 wt % and the content of the thermoplastic resin within the range of 0.05 to 20 wt %, and further a surface-treating method of applying said hard surface-treating agent or stain-proofing agent onto coated surfaces.